Physical inactivity and obesity are major concerns in most American Indian and Alaska Native communities, especially given their increasingly sedentary lifestyles, reliance on motor vehicles and modern conveniences* and the growing epidemic of obesity among Native youth and adults. Low physical activity and physical fitness levels in adults, independent of body weight, are linked to several adverse health outcomes, including diabetes and cardiovascular disease. Physical inactivity is thus likely one important modifiable factor explaining the high rates of diabetes and cardiovascular disease in American Indian and Alaska Native communities. Accordingly, the primary objective of this research is to determine the effects of a communitybased health program on physical activity levels and select health outcomes in sedentary and overweight/obese, middle-aged American Indian and Alaska Native adults living in the Seattle metropolitan area. The exercise intervention component in the present study will be based on a program developed and successfully implemented in our previous studies with non-Native adults. We will, therefore, modify the intervention to make it more culturally responsive to Native communities based, in part, on focus groups and other formative research that will be conducted during the early years of this Project EXPORT. Our Specific Aims are to 1) conduct a randomized, controlled trial testing the efficacy of a community-based health program for increasing physical activity in sedentary and overweight/obese, middle-aged American Indian and Alaska Native adults, 2) determine the effects of increasing physical activity on select health outcomes, including body mass index, waist circumference, and fasting blood measures (glucose, insulin, lipids, and high-sensitive c-reactive protein), and 3) examine the relationship between the built environment and compliance with the prescribed level of physical activity. We hypothesize that participants randomized to a community-based health program will have greater increases in physical activity and better health outcomes, such as greater decreases in waist circumference and fasting blood measures than those in a general health education program and participants living in neighborhoods with a higher walkability index be more compliant with the prescribed level of exercise than those living in neighborhoods with a lower walkability index. The investigators will partner with the Seattle Indian Health Board and tribal elders to design the intervention. We also will administer the intervention in the context of an ecological framework targeting multiple levels of behavior change (e.g., individual and community). Participation in the intervention will be facilitated through community sites such as elder groups, churches, recreation centers, and work places. This approach is intended to connect participants to the communities in which they live to further break down barriers to physical activity. It should be especially appealing to local community groups, health care organizations, and policymakers because the results would be readily generalizable and transferable to practice.